This is a nationalization of PCT/SE01/00687 filed Mar. 29, 2001 and published in English.
This invention concerns a surgical table according to the preamble of claim 1.
Surgical tables of today provide movements in various dimensions such as elevation of the table and tilting about the longitudinal as well as the transversal axis. These various movements are desirable for adoption to particular operating situations and also, in case of a surgical table having a radiolucent table top, i.a. for allowing freer X-ray imaging of a particular body part. In particular, lateral tilt is used for allowing organs to be imaged from different directions as desired and in some cases for displacing xe2x80x9cloosexe2x80x9d organs from each other or from xe2x80x9cfixedxe2x80x9d organs in order to obtain improved images.
EP-A2-0 923 922 concerns an operating table for surgical as well as imaging procedures. The table comprises a radiolucent table top and means for providing the table top with vertical lift, longitudinal tilt, lateral tilt and a four-way floating movement. A control switch is provided which is effective to permit floating movement of the table top along a horizontal axis and ineffective to permit floating movement along a tilted axis. The table top is thereby totally prevented from floating movement when tilted both longitudinally and laterally, it is free to float laterally, but not longitudinally when tilted only longitudinally, and it is free to float longitudinally but not laterally when tilted only laterally. When the table top is horizontal it is free to float in either direction.
According to EP-A2-0 923 922, lateral movement of the table top is thus not permitted when the table top is subjected to a lateral tilt and the reason for this is that when being laterally tilted there is a risk of the table top falling down to the lowermost position. Given that adult patients often weigh well over 100 kg, free movability in lateral directions could be dangerous for the patient as well as for the personnel, since it could jeopardise the stability of the entire table. The provision of automatic lock is therefore to be regarded as an important safety measure according to this EP document.
When examining a patient using imaging equipment, the table top is usually floated with respect to the fixed imaging equipment in order to obtain the best images of the organ to be examined. In the prior art device according to EP-A2-0 923 922, however, it is difficult for the surgeon to freely and flexibly scan the area around the organ of the patient to be examined in a lateral tilted position of the table top. In real time imaging as well as in X-ray photography the surgeon can only use the floating movement in the horizontal position of the table top, when freely locating and examining the patient. This is thus only possible before tilting the table top.
If free adjustment is desired or necessary after reaching a tilted position, the surgeon will either have to try to adjust the tilt or to adjust the position of the imaging equipment, which is typically arranged on a so called C-arm, partly enclosing the table top and the part of the patient to be imaged. This is, however difficult and results in inexact positioning. This limitation with respect to the possibilities of obtaining an overview of the patient""s organs as well as fine adjustment and flexibility has proved to be a serious drawback of the prior art.
It is an object of the invention to overcome the drawbacks of the prior art and to provide a surgical table, which allows greater flexibility with respect to handling and applicability. This object is attained with a surgical table according to the above through the features of the characterising portion of claim 1.
These features make it possible to achieve lateral movement in lateral directions of the table top also when the table top is subjected to a lateral tilt. This is possible because the lateral floating means are positioned so that they are unaffected by the lateral tilt. No particular power actuators are necessary for lateral movement even in lateral tilted positions of the table top since the lateral movement is unaffected by gravity forces. It should however be mentioned that the invention does not exclude using power assisted float.
As to the inventive surgical table, the table with the table top in all positions defines longitudinal directions along its longitudinal extension and lateral directions perpendicular thereto. The lateral tilting mechanism provides lateral tilting movement to the table top in parallel with the lateral directions. The lateral floating means is arranged such that it allows the table top floating horizontal movement in said lateral directions.
The invention brings along several advantages such as flexibility for the surgeon, increased accuracy and possibility of quicker diagnosis, which could be crucial with respect to the well-being of the patient and the success of the surgeon""s efforts. No movement of the entire surgical table is necessary and no fine adjustment of the image C-arm.
It should be noted that lateral movability in lateral tilted positions of the table top takes care of most imaging and operating situations. The table may or may not be arranged for allowing longitudinal movability when the table top is subject to longitudinal tilt, e.g. by power float means. Longitudinal tilt will, however, not influence the lateral movability. In most operating and imaging situations, however, the table top is not longitudinally tilted.
According to a preferred aspect of the invention, the lateral tilting actuators are comprised of linkage mechanisms, which are arranged so as to obtain lateral tilting movement of the table top about an axis or axes located above the table top. This gives a vertically compact solution and makes it possible to tilt the table top and the patient around a position close to the organ to be investigated.
It should be noted that tilting of the table top is important for several reasons. Longitudinal tilting around a transversal axis (Trendelenburg tilting) for example allows placing the head lower than the rest of the patient""s body, which compensates for low blood pressure in case of trauma. As has been mentioned above, lateral tilting around a longitudinal axis allows imaging from chosen directions. It also relocates certain organs such as the bowls thereby freeing other organs for examination. The invention makes it possible to fine adjust imaging in transversally tilted positions of the body, whereby the diagnosis may be enhanced and made quicker.
The aspect where the lateral tilting actuators are attached to first and second frames guarantees the stability of the construction. The frames also make it possible for a vertical carrier beam belonging to the base structure to extend through the insides of the frames, whereby the elevation path of the table top may be extended in an advantageous way (see claim 14).
According to a further aspect, the lateral tilting actuators may be comprised of program controlled actuators. These actuators are preferably located between first and second frames thereby guaranteeing the stability of the construction.
According to one further aspect, the provision of one part of the lateral floating means on the first frame provides for a simple and robust construction.